Double-knitted fabrics have been conventionally used in various fields. A tie yarn most popularly used for connecting a face cloth and a back cloth in such double-knitted fabrics is a usual finished yarn. These double-knitted fabrics are mainly used as back cloth in clothing and provide cushioning and heat insulating properties.
Double-knitted fabrics utilizing a heat-bonding fiber as the tie yarn are known, for instance, as knit fabric moldings such as bra cups as disclosed, for instance, in Japanese Patent Publication Kokai No. 4-240252. This is a molding utilizing the stretchability of knit fabric and the moldability of heat-bonding fiber.
In general, when such moldings are used as sewing articles such as seats for automobiles, they are required to have a great seam strength. However, the afore-mentioned molding of a knit fabric which is not particularly made for this purpose cannot hold a satisfactory seam strength. Thus, it is hard to apply such a knit fabric molding to a sewing article such as seats for automobiles or the like.
On the other hand, a three-layer structured knit fabric of two-way tricot is already put on the market, which is an article similar to the afore-mentioned knit fabric molding. In such a three-layer structured knit fabric, a monofilament is employed as the tie yarn in order to improve the cushioning property by a large elastic modulus, and a spandex is used in order to provide a stretchability in vertical and longitudinal directions despite being a tricot fabric. Consequently, such a three-layer structured knit fabric has the disadvantage of being expensive.
Unlike tricots, double-knitted fabrics which are ordinarily produced by using a circular knitting machine are provided with a stretchability in vertical and longitudinal directions through their knitting fabric without using spandex. However, a circular knitting machine cannot knit monofilaments having a large elastic modulus as used in two-way tricots.
Therefore, when producing double-knitted fabric, a heat-bonding yarn has been used as the tie yarn which is soft at the time of knitting and which presents a large elastic modulus after knitting. Double-knitted fabrics which are made by using a heat-bonding yarn as the tie yarn are known to be obtained by fusing the tie yarn through heat treatment after knitting to obtain a large elastic modulus.
However, for portions of articles at which a high cushioning property is required such as inner linings for shoes, tricots are still used at present. The reason why no double-knitted fabric has been used in such fields is that fatigue against repetitive load is large. Thus, if double-knitted fabrics which assume smaller fatigue against repetitive load can be easily manufactured, the uses thereof would be widen, since the manufacturing cost thereof is lower than that of tricots.
At present, various mouse pads for use with computers are sold, and most of them are those formed by laminating a polyurethane sponge onto a knit surface material. In such mouse pads, the surface material improves the gliding of the mouse, and the rolling of the ball is improved by providing the cushioning property. The urethane sponge also functions as a non-slip material between the mouse pad and a table. However, since the deformation amount against load largely differs between the surface material and the urethane sponge such mouse pads have the drawback that the surface material and the urethane sponge are easy to peel off when used over a long term.
In view of this drawback, three-layer structured knit fabrics such as double tricots are attracting attention as materials for mouse pads. The cushioning property of such a double tricot fabric can be varied by selecting a proper texture required for the mouse pads.
However, the knits such as double tricots do not present sufficient non-slip properties between the mouse pad and the table so that they cannot be used for mouse pads without any treatments. Further, they have the disadvantage that the cut portions thereof are easy to fray and accordingly has to be treated for runproofing.
The present invention has been made in view of the above-mentioned prior art, and it is an object of the present invention to provide a double-knitted fabric with an excellent moldability, a high seam strength and an excellent cushioning property, which is inexpensive and can be suitably used in various heat insulators, cushioning materials and moldings, and to provide moldings made thereof, and mouse pads which sensitively accommodate even to slight movements of a mouse used in connection with computers or the like.